Introduce VM API for the patching mechanism.

runtime/vm/dart_api_impl_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "platform/utils.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
@@ skipping 5655 matching lines @@
   recv = Dart_New(cls, Dart_Null(), 0, NULL);
   result = Dart_Invoke(recv, Dart_NewString("bar"), 0, NULL);
   EXPECT_VALID(result);
   EXPECT(Dart_IsString(result));
   result_cstr = "";
   EXPECT_VALID(Dart_StringToCString(result, &result_cstr));
   EXPECT_STREQ("bar", result_cstr);
 }
 
 
+TEST_CASE(LoadPatch) {
+  const char* kLibrary1Chars =
+      "#library('library1_name');";
+  const char* kSourceChars =
+      "external int foo();";
+  const char* kPatchChars =
+      "patch int foo() => 42;";
+
+  // Load up a library.
+  Dart_Handle url = Dart_NewString("library1_url");
+  Dart_Handle source = Dart_NewString(kLibrary1Chars);
+  Dart_Handle lib = Dart_LoadLibrary(url, source);
+  EXPECT_VALID(lib);
+  EXPECT(Dart_IsLibrary(lib));
+
+  url = Dart_NewString("source_url");
+  source = Dart_NewString(kSourceChars);
+
+  Dart_Handle result = Dart_LoadSource(lib, url, source);
+  EXPECT_VALID(result);
+
+  url = Dart_NewString("patch_url");
+  source = Dart_NewString(kPatchChars);
+
+  result = Dart_LoadPatch(lib, url, source);
+  EXPECT_VALID(result);
+
+  result = Dart_Invoke(lib, Dart_NewString("foo"), 0, NULL);
+  EXPECT_VALID(result);
+  EXPECT(Dart_IsInteger(result));
+  int64_t value = 0;
+  EXPECT_VALID(Dart_IntegerToInt64(result, &value));
+  EXPECT_EQ(42, value);
+}
+
+
 static void PatchNativeFunction(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_SetReturnValue(args, Dart_Null());
   Dart_ExitScope();
 }
 
 
 static Dart_NativeFunction PatchNativeResolver(Dart_Handle name,
                                                int arg_count) {
   return &PatchNativeFunction;
@@ skipping 1460 matching lines @@
     EXPECT(o2 == reinterpret_cast<void*>(&p2));
   }
   Dart_ExitScope();
   isolate->heap()->CollectGarbage(Heap::kOld);
   EXPECT_EQ(0, isolate->heap()->PeerCount());
 }
 
 #endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart